Process for the preparation of substituted benzenes and benzene sulfonic acid and derivatives thereof and a process for the preparation of N,N&#39;-substituted ureas

ABSTRACT

A process for the preparation of substituted benzenes or benzenesulfonic acid and its derivatives comprising diazotisation of an aminobenzene or ortho-amino-benzenesulfonic acid derivative followed by homogeneous palladium-catalyzed coupling with an olefine and heterogeneous palladium-catalyzed hydrogenation of the olefinic substituent, wherein the homogeneous catalyst is reduced and precipitated as metal after the coupling in the reaction mixture and used as a heterogeneous palladium catalyst for the hydrogenation step. The process is particular suitable for the preparation N-benzenesulfon-N&#39;-triazinyl-urea herbicides.

This is a continuation of Ser. No. 08/315,313, filed Sep. 29, 1994,abandoned, which is a continuation of Ser. No. 08/093,213, filed Jul.19, 1993, abandoned, which is a continuation-in-part of Ser. No.07/932,135, filed Aug. 18, 1992, abandoned.

The present invention relates to an improved process for the preparationof substituted benzenes and benzenesulfonic acid and its derivativescomprising diazotisation of an ortho-amino-benzenesulfonic acidderivative followed by homogeneous palladium-catalysed coupling andheterogeneous palladium-catalysed hydrogenation, wherein the homogeneouscatalyst is reduced and precipitated as metal after the coupling andused as a heterogeneous palladium catalyst for the hydrogenation stepwithout separation. The present invention further relates to a processfor the preperation N-benzenesulfonyl-N'-triazinyl-ureas.

Benzene sulfonic acid derivatives may be used as intermediates in theproduction of agricultural chemicals. The preparation ofN-phenylsulfonyl-N'-pyrimidinyl ureas with plant growth-regulatingproperties from benzene sulfonic acid salts is described, for example,in EP-A- 120814.

Stepwise processes are known in which an aryl-alkene coupling catalysedby Pd(0) is followed by isolation and subsequent catalytichydrogenation. The "Heck" reaction involves the coupling of an alkenewith an arylhalide, while the "Matsuda" version of the Heck reactionproceeds via more reactive adducts e.g. an aryl diazonium ion asdescribed, for example, in Tetrahedron Vol. 37 p. 31 to 36 (1981).Stepwise procedures are described, for example, in EP-A-120814 and by M.Somei et al. in Heterocycles, vol. 26, No. 7., p. 1783 to 1784 (1987).

Nevertheless a process for the preparation of substitutedbenzenesulfonic acid and its derivatives in which separation of thepalladium catalyst is avoided and the palladium is used in bothhomogeneous and heterogeneous reaction steps is not known.

Surprisingly it has now been found that a homogeneous aryl-couplingreaction with olefines catalysed by a homogeneous palladium complex canbe followed by a hydrogenation step in which the palladium fromhomogeneous palladium complex is used for the heterogeneoushydrogenation step as Pd metal, after which the palladium may berecovered by filtration and refined by known procedures to regeneratefor example the starting complex.

It is therefore an object of the invention to provide an elegant doubleuse of the palladium catalyst and to provide a more economic process inwhich a soluble palladium catalyst is used in the Matsuda homogeneousstep and then used in the heterogeneous hydrogenation step.

One object of the invention is a process for the preparation ofcompounds of the formula Ia

    Ar--CHR.sub.a --CHR.sub.b R.sub.c                          (Ia),

wherein R_(a), R_(b) and R_(c) are independently of each other H or ahydrogenation stable substituent and Ar means C₆ -C₂₀ aryl or C₃ -C₂₀heteroaryl having 1 to 6 heteroatoms from the group of O, S and N, thearyl and heteroaryl being unsubstituted or substituted by hydrogenationstable residues, by

a) in a first step reacting 1 mole equivalent of a compound of theformula II

    Ar-N.sub.2.sup.⊕                                       (IIa)

with at least 1 mole equivalent of a compound of formula IIIa

    CHR.sub.a ═CR.sub.b R.sub.c                            (IIIa),

optionally in the presence of an inert solvent, and in the presence of acatalytic amount of a homogeneous palladium catalyst and a base selectedfrom alkali metal salts, alkaline earth metal salts and a tertiaryammonium salt of a carboxylic acid to give a compound of the formula IVa

    Ar--CR.sub.a ═CR.sub.b R.sub.c                         (IVa),

and

b) hydrogenating in a second step the compound of the formula IVaoptionally in the presence of an inert solvent and in the presence ofcatalytic amounts of a palladium hydrogenation catalyst, characterisedin that the homogeneous palladium catalyst is reduced to insolublepalladium metal in the step a) reaction mixture, which is subsequentlyused as the heterogeneous hydrogenation catalyst.

A preferred variant of the process according to the invention ischaracterised in that the heterogeneous palladium hydrogenation catalystis formed in situ from the homogeneous palladium catalyst in theobtained step a) reaction mixture in starting the hydrogenation byintroducing hydrogen.

It is very preferred to add a palladium support material for theheterogeneous hydrogenation catalyst.

The Matsuda version of the Heck reaction works in a wide scope withcompounds of the formula Ia so that substituents R_(a), R_(b) and R_(c)may be choosen from various groups of organic residues.

R_(a), R_(b) and R_(c) may be selected from H; C₁ -C₂₀ alkyl; C₁ -C₂₀nitriloalkyl; C₁ -C₂₀ hydroxyalkyl; C₁ -C₂₀ halogenalkyl, halogen beingpreferably F, Cl or Br; C₁ -C₁₂ alkyl-COOR_(d), C₁ -C₁₂ alkyl-CO--NR_(e)R_(f), C₁ -C₁₂ alkyl-SO₂ OR_(d) or C₁ -C₁₂ alkyl-SO₂ --NR_(e) R_(f),wherein R_(d), R_(c) and R_(f) independently are H, C₁ -C₁₂ alkyl,phenyl, benzyl or cyclohexyl; C₁ -C₂₀ alkyl-CO; C₁ -C₂₀ alkoxy; C₁ -C₂₀nitriloalkoxy; C₁ -C₂₀ halogenalkoxy, halogen being preferably F, Cl orBr; C₁ -C₂₀ alkylthio; C₁ -C₂₀ halogenalkylthio, halogen beingpreferably F, Cl or Br; --SO₂ OR_(d), --SO₂ --NR_(e) R_(f), --COOR_(d)or --CO--NR_(e) R_(f), wherein R_(d), R_(e) and R_(f) have the abovemeanings; halogen which is preferably F, Cl or Br; --CN; --NR_(e) R_(f),wherein R_(e) and R_(f) have the above meanings; phenyl or benzyl whichis unsubstituted or substituted by C₁ -C₂₀ alkyl; C₁ -C₂₀ nitriloalkyl;C₁ -C₂₀ hydroxyalkyl; C₁ -C₂₀ halogenalkyl, halogen being preferably F,Cl or Br; C₁ -C₂₀ alkyl-COOR_(d), C₁ -C₁₂ alkyl-CO--NR_(e) R_(f), C₁-C₁₂ alkyl-SO₂ OR_(d) or C₁ -C₁₂ alkyl-SO₂ --NR_(e) R_(f), whereinR_(d), R_(e) and R_(f) independently are H, C₁ -C₁₂ alkyl, phenyl,benzyl or cyclohexyl; C₁ -C₂₀ alkyl-CO--; C₁ -C₂₀ alkoxy; C₁ -C₂₀nitriloalkoxy; C₁ -C₂₀ halogenalkoxy, halogen being preferably F, Cl orBr; C₁ -C₂₀ alkylthio; C₁ -C₂₀ halogenalkylthio, halogen beingpreferably F, Cl or Br; --SO₂ OR_(d), --SO₂ --NR_(e) R_(f), --COOR_(d)or --CO--NR_(e) R_(f), wherein R_(d), R_(e) and R_(f) have the abovemeanings; halogen which is preferably F, Cl or Br; --CN; --NR_(e) R_(f),wherein R_(e) and R_(f) have the above meanings. R_(d) may alsorepresent --OM or --O(M₁)_(1/2), where M is an alkali metal atom or atertiary ammonium group, having from 3 to 18 carbon atoms, and M₁ is analkaline earth metal atom. All alkyl, alkoxy and alkylthio groupscontain preferably 1 to 12 carbon atoms, more preferably 1 to 8 carbonatoms and most preferably 1 to 4 carbon atoms.

Ar as aryl contains preferably 6 to 16, more preferably 6 to 12 carbonatoms and Ar may be monocyclic or condensed polycyclic aryl, whereby thepolycyclic aryl may contain up to 5 and preferably up to 3 rings.Preferred Ar-groups are naphthyl and especially phenyl. The heteroarylcontains preferably 3 to 14, more preferably 3 to 10 carbon atoms,having preferably 1 to 4 and more preferably 1 to 3 heteroatoms from thegroup of O, S and N, whereby N is especially preferred. The heteroarylmay be monocyclic or condensed polycyclic heteroaryl, whereby thepolycyclic heteroaryl may contain up to 5 and preferably up to 3 rings.Preferred heteroaryl is pyridine, triazine, pyrimydine and chinoline.

The aryl and heteroaryl may be substituted independently by the groupsas mentioned above for R_(a), R_(b) and R_(c) and also by --OH or --SH.

The reaction conditions may vary in broad range but may be preferablyselected as for the more preferred object described below.

A more preferred object of the invention is a process for thepreparation of compounds of the formula I ##STR1## wherein X representshydroxyl, --OM, --O(M1)_(1/2) or NH₂, where M is an alkali metal atom ora tertiary ammonium group, having from 3 to 18 carbon atoms, and M₁ isan alkaline earth metal atom,

Y is H, Cl, F or Br,

R₁ is H, F, Cl, Br or --COOR₃,

R₂ is --COO(C₁ -C₄ -alkyl), --(CO)R₃ or C₁ -C₂ -alkyl which isunsubstituted or substituted by halogen atoms, and

R₃ is H or C₁ -C₄ -alkyl, by

a) in a first step reacting 1 mole equivalent of a compound of theformula II ##STR2## with at least 1 mole equivalent of a compound offormula III

    CHR.sub.1 ═CHR.sub.2                                   (III),

optionally in the presence of an inert solvent, and in the presence of acatalytic amount of a homogeneous palladium catalyst and a base selectedfrom alkali metal salts, alkaline earth metal salts and a tertiaryammonium salt of a carboxylic acid to give a compound of the formula IV##STR3## and

b) hydrogenating in a second step the compound of the formula IVoptionally in the presence of an inert solvent and in the presence ofcatalytic amounts of a hydrogenation catalyst, characterised in that thehomogeneous palladium catalyst is reduced to insoluble palladium metalin the step a) reaction mixture, which is subsequently used as theheterogeneous hydrogenation catalyst.

A preferred variant of this process is characterised in that theheterogeneous palladium hydrogenation catalyst is formed in situ fromthe homogeneous palladium catalyst in the obtained step a) reactionmixture in starting the hydrogenation by introducing hydrogen.

It is very preferred to add a palladium support material for theheterogeneous hydrogenation catalyst.

M in the above definition is preferably lithium, sodium or potassium. M₁is preferably magnesium or calcium. M₁ as tertiary ammonium may berepresented by the formula R₄ R₅ R₆ NH⁺, wherein R₄, R₅ and R₆independently are C₁ -C₆ -alkyl, preferably C₁ -C₄ -alkyl, or R₄ and R₆together are --(CH₂)₄ --, --(CH₂)₅ -- or --(CH₂)₂ O(CH₂)₂ -- and R₆ isC₁ -C₆ -alkyl, preferably C₁ -C₄ -alkyl. Some examples for alkyl aremethyl, ethyl, n- or i-propyl, n-, i- or t-butyl.

In the above definition alkyl denotes straight chain or branched alkyl,e.g. methyl, ethyl, n-propyl, isopropyl, and the four isomers of butyl.

The halogen substituent for R₂ as C₁ -C₂ -alkyl is preferably F or Cl.

R₁ is preferably H, and R₂ is preferably --CF₃, --CF₂ Cl, -CFCl₂,--CCl₃, --COO(C₁ -C₄ -alkyl) or --(CO)CH₃. In an especially preferredembodiment, R₁ is H and R₂ is --CF₃ or --(CO)CH₃.

X is preferably OH, ONa or OK. Y is preferably H.

The starting point of the process according to the invention is an aryldiazonium cation of formula II which may be formed by methods welldocumented in the literature.

The diazonium compound of formula II may be formed in situ by well-knownmethods, or added as a salt, in which case examples of the counter anionfor the compounds of formula II are PF₆ ⁻, BF₄ ⁻,OAc⁻, HSO₄ ⁻, SO₄ ²⁻,CH₃ (C₆ H₄)SO₃ ⁻ and CH₃ SO₃ ⁻. The in situ formation may also be cardedout in the presence of compounds of formula III, for example with theaddition of alkylnitrites such as t-butyl nitrite as described in J.Org. Chem. Vol. 46, p. 4885 to 4888 (1981).

The palladium catalyst used in the first reaction step may be generatedin situ or ex situ by reduction of a palladium(II) compound optionallyin the presence of a salt such as sodium acetate and in the presence ofsuitable ligand-forming compounds. Suitable palladium compounds includePdCl₂, PdBr₂, Pd(NO₃)₂, H₂ PdCl₄, Pd(OOCCH₃)₂, [PdCl₄ ]Na₂, [PdCl₄ ]Li₂,[PdCl₄ ]K₂, palladium(II)acetylacetonate,dichloro-(1,5-cyclooctadiene)palladium(II),dichlorobis-(acetonitrile)palladium(II),dichlorobis-(benzonitrile)palladium(II), π-allylpalladium(II)chloridedimer, bis-(π-methylallyl palladium(II)chloride) andπ-allylpalladium(II)acetylacetonate. Suitable ligand-forming compoundsare for example olefins as described by the compounds of formula III,dibenzylideneacetone (dba) unsubstituted or substituted with halogen (F,Cl and Br), C₁ -C₄ -alkyl or C₁ -C₄ -alkoxy in the benzene rings,phosphites such as those of formula P(OR₇) wherein R₇ is for examplephenyl, C₁ -C₆ -alkyl or a partially or perfluorinated C₁ -C₆ -alkyl,and CO. The substituents in the benzene rings are preferably linked inthe para-positions of the benzene rings. The ligand forming compoundsmay be used alone or in combinations of at least two compounds.

Suitable reducing agents are for example CO, H₂, formates, primary orsecondary C₁ -C₈ -alkanols, hydrazine, amines and mixtures of CO withalkanols or water.

The catalyst may be added as Pd(dba)₂, Pd(dba)₃.solvent, Pd₂ (dba)₃ orPd2(dba)3.solvent, where the abbreviation "dba" stands for dibenzylideneacetone. The dba ligand may be unsubstituted or substituted in thearomatic part as described above.

The palladium catalyst may be used in an amount of about 0.01 to 5 mole%, based on the diazonium salt of formula II.

The base added in the first reaction step is used as a buffer toneutralise the acids present in the formation of the diazonium salts.The base may be used in at least equimolar amounts related to thediazonium compounds of formula II and preferably in an excess of up to10 moles. Suitable bases are Li--, Na--, K--, NH₄ --, Mg--, Ca-- andNH(C₁ -C₁₈ -alkyl)₃ -salts of carboxylic acids such as C₁ -C₄-carboxylic acids or benzoic acid. Examples of suitable bases arelithium, potassium or sodium -acetate, -butyrate, -propionate andstearate, barium- and calcium acetate, calcium propionate and -stearate,lithium and sodium benzoate, and ammonium acetate; salts of acetic acidwith triethylamine, tri-n-butylamine, tri-(2-ethylhexylamine),tri-n-octylamine and tri-n-dodecylamine. Especially preferred arealkaline metal acetates, which form acetic acid as a desirable componentin the arylation step. Particularly preferred bases are sodium andpotassium acetate in excess. The bases may also be used as salts in thecatalyst generation described above.

A stoichiometric amount or small excess of alkene of formula Ill ispreferred.

After the first reaction step, the homogeneous catalyst is reduced toform a heterogeneous catalyst. It is advantageous to use H₂ as reducingagent, since the addition of a further reactand can be avoided. It isvery advantageous to add a support material for the palladium catalystfor the hydrogenation step, said support material being inert under thereaction conditions. The presence of the catalyst support or carrier canfacilitate the separation of the catalyst on completion of the reaction.Examples of suitable support materials are activated carbon, carbonblack, metal oxides e.g. Al₂ O₃ and SiO₂, ceramics, glass and silicatese.g. synthetic and naturally occurring zeolites. Activated carbon orcarbon black are preferred. The weight ratio of the catalyst support tothe homogeneous palladium catalyst may be for example from 50:1 to 1:1,preferably from 20:1 to 1:1 and more preferred from 15:1 to 2:1.

The reaction temperature for the coupling step should be below thedecomposition temperature of the diazonium ion, and a suitable range isbetween -20° and +40° C. The hydrogenation step can be carried outbetween room temperature and 200° C. To minimise side reactions it isadvantageous to carry out the coupling step under elevated partialpressure of the coupling component of formula III, for example up to 10bar, preferably between atmospheric pressure and 2 bar (1 bar=1×10⁵Pascals).

It is advantageous to carry out the hydrogenation stage of the processaccording to the invention at an elevated pressure, for example up to 40bar. The hydrogen partial pressure is preferably between atmosphericpressure and 3×10⁶ Pascals.

Solvents for the process according to the invention may be, for exampleone of, or a mixture of at least one of the following: alcohols;ketones; carboxylic acids; sulfones; N,N-tetrasubstituted ureas;N-alkylated lactams or N-dialkylated acid amides; ethers; aliphatic,cycloaliphatic or aromatic hydrocarbons, which may be substituted withfluorine, chlorine, or C.sub. -C₄ -alkyl; carboxylic acid esters andlactones; nitriles.

Some specific examples of solvents are:

alcohol: methanol, ethanol, propanol, butanol, pentanol, isopropanol,hexanol, heptanol octanol, t-butylalcohol, ethyleneglycol anddiethyleneglycol.

ketone: acetone, methylethylketone, methylisobutylketone, cyclohexanone.

carboxylic acid: ethanoic acid, propanoic acid.

sulfone: dimethylsulfone, diethylsulfone, tetramethylenesulfone,sulfolan.

N,N-tetrasubstituted urea: N-methylethyl-N'-methylethylurea,N-dimethyl-N'-dipropylurea, tetramethylurea, tetraethylurea,N,N'-dimethyl-N,N'-1,3-propyleneurea, N,N'-dimethyl-N,N'-ethyleneurea.

N-alkylated lactam: N-methylpyrrolidone, N-ethylpyrrolidone.

N-dialkylated acid amide: N-dimethylformamide, N-diethylformamide,N-dimethylacetamide.

ether: polyethylglycolether, diethyleneglycoldimethylether,diethyleneglycoldiethylether, tetrahydrofuran, dioxan,methyl-t-butylether, diethyleneglycolmonomethylether andethyleneglycolmonomethylether.

aliphatic hydrocarbon: methylene chloride, pentane, hexane.

cycloaliphatic hydrocarbon: cyclohexane, decahydronaphthalene.

aromatic hydrocarbon: xylene, tetrahydronaphthalene, dichlorobenzene.

carboxylic acid ester: benzoic-methylester, ethylacetate,7-butyrolactone, n-butylacetate.

nitrile: acetonitrile, benzonitrile, phenylacetonitrile.

It may be advantageous to use an ether/water, an ether/alcohol or analcohol/water mixture as solvent for the diazotisation. The arylationstep is preferably carried out under water-free reaction conditions.Water present in the diazotisation is preferably removed by the additionof carboxylic acid anhydrides such as acetic anhydride or by otherwell-known methods.

A further object of the invention is the reaction procedure in analcohol as solvent, for example pentanol or isopropanol, which issurprising in view of the observation made in Tetrahedron Vol. 37, p. 31(1981) that the use of alcoholic solvent caused reduction of diazoniumsalts.

Preferred solvents are butanol, pentanol, isopropanol, acetonitrile,ethanoic acid and dioxan or mixtures of these solvents.

A preferred embodiment of the process according to the invention is thatthe reaction is carried out as a one-pot reaction.

The process according to the invention has the following advantages:

i) The catalytic material is used in two consecutive and differentreaction steps. The homogeneous catalyst for the Matsuda reaction isconverted in situ into the necessary heterogeneous hydrogenationcatalyst for the next step.

ii) The catalyst is recovered by filtration at the end of thehydrogenation step.

iii) More efficient use is made of the catalytic material.

iv) The palladium catalyst may be recycled from the reaction medium withnegligible loss.

v) Mild conditions are used.

vi) Purer product is obtained in a higher yield.

vii) Elegant double use of expensive palladium is achieved.

viii) The process can be carried out in alcoholic solvents.

ix) Isolation of intermidiate is avoided.

x) Economic production of herbicides (sulfonyl-ureas) on an industrialscale.

It is desirable to recycle the catalyst following hydrogenation. Thiscan be achieved by known methods.

A further object of the invention is a process for the manufacture ofcompounds of the formula V ##STR4## wherein X₁ is S or O, X₂ is N or CH,

Y is H, Cl, F or Br,

R₁ is H, F, Cl, Br or --COOR₃,

R₂ is --COO(C₁ -C₄ -alkyl), --(CO)R₃ or C₁ -₂ -alkyl which isunsubstituted or substituted by halogen atoms, and

R₃ is H or C₁ -C₄ -alkyl,

R₈ is H, C₁ -C₃ alkyl or C₁ -C₃ alkoxy

R₉ is C₁ -C₃ alkyl, C₁ -C₃ haloalkyl, C₁ -C₃ alkoxy or C₁ -C₃haloalkoxy, and

R₁₀ is H, halogen, NH₂, NH(Cl₁ -C₃ alkyl), NH(C₁ -C₃ alkyl)₂, C₁ -C₃alkyl, C₁ -C₃ haloalkyl,

C₁ -C₃ alkoxy or C₁ -C₃ haloalkoxy, by

a) reacting in a first step 1 mole equivalent of a compound of theformula IIb ##STR5## wherein X₃ represents hydroxyl, --OM or--O(M₁)_(1/2), where M is an alkali metal atom or a tertiary ammoniumgroup, having from 3 to 18 carbon atoms, and M₁ is an alkaline earthmetal atom, with at least 1 mole equivalent of a compound of formulaIIIb

    CHR.sub.1 ═CHR.sub.2                                   (IIIb),

optionally in the presence of an inert solvent, and in the presence of acatalytic amount of a homogeneous palladium catalyst and a base selectedfrom alkali metal salts, alkaline earth metal salts and a tertiaryammonium salt of a carboxylic acid to give a compound of the formula IVb##STR6## and

b) hydrogenating in a second step the compound of the formula IVboptionally in the presence of an inert solvent and in the presence ofcatalytic amounts of a hydrogenation catalyst, to form a compound of theformula Ib ##STR7##

c) reacting in a third step the compound of formula Ib with at least 1mole of a halogenating agent to form the sulfochloride, which is thenreacted with NH₃ to give the sulfonamide of the formula Ic ##STR8##

d) reacting the compound of the formula Ic with COCl₂ or CSCl₂ to obtaina compound of the formula VI ##STR9##

e) reacting the compound of the formula VI with a compound of theformula VII ##STR10## to form the compound of the formula V,characterised in that the homogeneous palladium catalyst is reduced toinsoluble palladium metal in the step a) reaction mixture, which issubsequently used as the heterogeneous hydrogenation catalyst.

A preferred variant of this process is characterised in that theheterogeneous palladium hydrogenation catalyst in the step b) reactionis formed in situ from the homogeneous palladium catalyst in theobtained step a) reaction mixture in starting the hydrogenation byintroducing hydrogen.

It is very preferred to add prior to the start of the hydrogenation asolid palladium support material for the heterogeneous hydrogenationcatalyst.

The preferred embodiments for the production of compounds of the formulaI applies also in the above steps a) and b) reactions. X₃ preferablyrepresents hydroxyl or a group --OM, wherein M is is an alkali metal,preferably K or Na.

X₁ is preferably O. X₂ is preferably N. R₈ is preferably H. R₉ ispreferably C₁ -C₃ alkyl, especially methyl or ethyl. R₁₀ is preferablyC₁ -C₃ alkyl, especially methyl or ethyl, or C₁ -C₃ alkoxy, especiallymethoxy or ethoxy.

The process is especially used for the production ofN-(4-methoxy-6-methyl-1,3,5-triazine-2-yl)-N'-[2-(3,3,3-trifluoroprop-1-yl)-benzenesulfonyl]-urea.

Reaction steps c), d) and e) are well known and described for example inU.S. Pat. No. 4,780,125. More preferred embodiments of these reactionsteps are described below.

In the step c) reaction the preferred halogenating agent is COCl₂ whichmay be used in excess, for example 2 to 3 mole excess. The reaction maybe catalyzed by the addition of N-dialkyl carboxylic acid amides likedimethylformamide, or by lactames like N-methylpyrrolidone. Catalyticamounts are for example 0.001 to 10 mole percent related to the amountof compound Ib. The reaction can be carded out under normal pressure orelevated pressure of up to 10 bar, preferably up to 5 bar. Thetemperature may be from 20° to 150° C., preferably 60° to 120° C.Solvents may be used as those mentioned before. Preferred arehalogenated hydrocarbons, especially chlorobenzene.

The sulfochloride is preferably treated without isolation in theobtained reaction mixture with acqueous NH₃ in a concentration ofpreferably 20 to 40% at temperatures of preferably 20° to 100° C., morepreferably 40° to 80° C. After cooling of the reaction mixture thecompound of formula Ic precipitates and may be filtered off.

The step d) reaction is preferably carded out with an excess of phosgeneor thiophosgene, for example 2 to 5 moles and preferably 2 to 3 moles.The reaction temperature is preferably 50° to 180° C. and morepreferably 70° to 150° C. The reaction is preferably catalyzed by theaddition of aliphatic or cycloaliphatic isocyanates having 1 to 10carbon atoms like cyclohexylisocyanate. Catalytic amounts are forexample 0.001 to 10 mole percent related to the amount of compound Ic.The reaction can be carded out under normal pressure or elevatedpressure of up to 10 bar, preferably up to 5 bar. Solvents may be usedas those mentioned before. Preferred are halogenated hydrocarbons,especially chlorobenzene.

The step e) reaction is preferably carried out in the presence of asolvent as those previously mentioned, especially halogenatedhydrocarbons as chlorobenzene. A preferred temperature range is from 20°to 180° C., especially 50° to 150° C. The reaction is in general cardedout under normal pressure or an elevated pressure of up to 1 bar.Equivalent molar ratios of the compounds of the formulae VI and VII arepreferred. In a preferred embodiment the obtained reaction solution withthe isocyanate of formula VI is added to the solution or suspension ofthe compound of the formula VII. After cooling of the reaction mixturethe compound of the formula V may be filtered off and may be purified bywashing the filter cake with a mineral acid like hydrochloric acid andthen with an alcanol like methanol. The product is obtained in highyields (90% or more) and purity (content at least 95% and up to morethan 99%). The inventive process is economic, ecologic, technicallyfeasible and save even on an industrial scale.

The following examples illustrate the invention.

EXAMPLE 1 Preparation of sodium trifluoropropyl-benzenesulfonate (inisopropanol)

a) Preparation of diazosulfonate

173.3 g aniline-2-sulfonic acid (1 mol) are stirred into 750 gisopropanol (IPA) together with 75 g water at 15° to 20° C. in a 1.5 dm³double-sleeve vessel. 89 g isopropylnilrite (IPN*) (1 mol) are addeddropwise to the reaction mixture over 60 minutes while stirring iscontinued at between 15° and 20° C. Any unreacted IPN is consumed by theaddition of dilute aniline-2-sulfonic acid. The diazo suspensionobtained is cooled and stored at between 0° and 5° C.

b) Preparation of sodium trifluoropropyl-benzenesulfonate

The diazo suspension from 1a) is transferred to a pressure vesselequipped with a pressure regulator. 123 g dry sodium acetate (1.5 mol)are added and the mixture stirred for 1 hour. 3 g Pd(dba)₂ (0.005 mol)are added, the mixture stirred for 5 minutes and the reaction vesselclosed. At 1 bar and with the temperature between 5° and 10° C. 106 g3,3,3-trifluoropropene (1.1 mol) are introduced over a 4 hour period.After the first hour the temperature is increased to 27° to 28° C. andkept there until no more nitrogen is evolved. Approximately 25 dm³ gasare evolved. The reaction mixture is transferred into a double-sleevedreaction vessel, 500 ml water added and the isopropanol is distilled offas an azeotrope isopropanol/water at atmospheric pressure. The aqueoussolution containing 255 g sodium trifluoropropyl-benzenesulfonate iscooled to room temperature.

c) Preparation of sodium trifluoropropyl-benzenesulfonate

The reaction mixture from 1b) is transferred into a hydrogenationautoclave and 20 g activated carbon are added. The hydrogenation iscarried out at 1 bar and 30° to 40° C. for 6 to 8 hours. The catalyst isfiltered off and washed with 100 ml water. The aqueous filtrate contains256 g of the title compound, determined by high pressure liquidchromatography. The aqueous solution of sodiumtrifluoropropyl-benzenesulfonate (1020 g) can be converted to thecorresponding sulfonamide (1d) via the acid chloride.

d) Characterisation of the title compound

The title sodium salt may be characterised by conversion to thecorresponding sulfonamide via the respective acid chloride.

1020 g 27% aqueous solution of sodium trifluoropropyl benzene sulfonate(1 mol) are acidified with 75 g 32% HCl to pH 1. 400 g water areevaporated off at 55° to 62° C. under 150 mbar vacuum. 1385 gchlorobenzene are added and a further 235 g water removed under 280 mbarvacuum. 15.4 ml dimethylformamide are added and the reaction mixtureheated to between 100° and 105° C. The temperature remains at this leveland 281 g phosgene are admitted over a 10-hour period. After 30 minstirring, the vessel is evacuated to 400 mbar and 215 ml chlorobenzenedistilled off at between 90° and 105° C. The suspension is filtered atroom temperature and washed with chlorobenzene. The clear brown filtratecontaining the corresponding sulfochloride is warmed to between 55° and60° C. and 155 g 30% ammonia added dropwise over a 30 min period. Afterstirring for a further 15 min, 4.5 g activated charcoal are added. About106 g water are evaporated off and the dry suspension diluted with 410ml chlorobenzene. The suspension (NH₄ Cl) is filtered over a prewarmedsuction filter treated with hyflo and the filtercake washed with 165 mlhot chlorobenzene. After crystallisation the suspension is cooled slowlyto between 0° and 5° C. The suspension is stirred for 30 min andfiltered. The filtercake is washed with cold chlorobenzene and dried ina vacuum chamber at 70° C. 229 g trifluoropropyl benzene sulfonamide areobtained.

EXAMPLE 2 Preparation of sodium trifluoropropyl-benzenesulfonate (inethanoic acid)

a) Preparation of diazosulfonate

244.6 g 88.5% aniline-2-sulfonic acid (1.25 mol) are stirred into 900 mldry ethanoic acid at room temperature. 85.8 g 96% sulfuric acid are runinto the reaction mixture over 30 minutes while stirring is continued.The suspension is cooled to between 18° and 20° C. 215.6 g 40% aqueoussodium nitrite solution (1.25 mol) are added dropwise to the reactionmixture at between 18° and 20° C. which is stirred for a further 30minutes. 3 ml 16.7% aqueous aniline-2-sulfonic acid are stirred in toconsume any excess nitrite. Over a period of 3 hours at between 20° and24° C., 497.5 g ethanoic anhydride (4.87 mol) are added, and afterstirring for a further 1 hour, the resulting yellow suspension is cooledto between 12° and 15° C.

b) Preparation of sodium trifluoropropenyl-benzenesulfonate

The diazo suspension from 2a) is transferred to a 2.5 dm³ vessel. Atbetween 15° and 17° C. 220 g sodium acetate (2.68 mol) are added and themixture is stirred for 1 hour. The temperature rises to 20° to 24° C.and stirring is continued for 45 minutes. With the temperature at 24°C., 3.6 g Pd(dba)₂ are added and the mixture stirred for 5 minutes. 130g 3,3,3-trifluoropropene (1.35 mol) are introduced over a 4 hour period.A mildly exothermic reaction follows and the temperature remains atbetween 25° and 28° C. for a further 30 minutes until no more nitrogenis evolved. Approximately 34 dm³ gas are evolved. The ethanoic acid isdistilled off under vacuum (200 mbar) at a temperature of 70° to 90° C.When the distillation residue weight has fallen to between 850 and 900g, 550 ml water are added and the mixture stirred at between 60° and 65°C.

c) Preparation of sodium trifluoropropyl-benzenesulfonate

The reaction mixture from 2b) is transferred into a hydrogenationautoclave and 35 g activated carbon are added. The hydrogenation iscarried out at a pressure of 1 bar and a temperature of between 30° and40° C. for 6 to 8 hours. The palladium-containing catalyst is separatedby filtration and washed with 120 ml water; the aqueous filtratecontains 314 g of the title compound, determined by HPLC, and less than2 ppm Pd. The aqueous solution of sodiumtrifluoropropyl-benzenesulfonate can be converted directly to thecorresponding sulfonamide as described in 1d) or isolated as follows:The aqueous solution of sodium trifluoropropyl-benzenesulfonate isconcentrated to 800 g. At 65° to 70° C. approximately 330 g 30% NaOH areadded until a pH of 9 is reached, when the product precipitates. Aftercooling to room temperature the suspension is filtered and washed with400 ml 25% NaCl brine in 4 portions. The wet cake is dried in a vacuumoven at 80° C. 420 g sodium trifluoropropenyl-benzenesulfonate areobtained (assay 70% determined by LC analysis).

EXAMPLE 3 Preperation ofN-(4-methoxy-6-methyl-1,3,5-tiazine-2-yl)-N'-[2-(3,3,3-trifluoroprop-1-yl)-benzenesulfonyl]-ureain a pilot plant

The following reactions are carried out in enamelled 630 l vessels.

a) Preperation ofsodium-[2-(3,3,3-trifluoro-1-propenyl)]-benzene-sulfonate.

Aniline-2-sulfonic acid is diazotised with pentylnitrite (molar ratio1:1.05) at 15° to 20° C. in pentanol containing up to 10% water assolvent. Excess pentylnitrite is destroyed with sulfamic acid and thewater is converted to acetic acid by adding acetic acid anhydride.Sodium acetate (molar ratio aniline-2-sulfonic acid to sodium acetate1:2) is added and stirring is continued for 90 minutes at 20° to 30° C.

In a seperate stainless steel vessel, dibenzylideneacetone (molar ratiodiazonium salt to dibenzylideneacetone 1:0.04) and sodium acetate (molarratio diazonium salt to sodium acetate 1:0.1) are mixed in pentanole anda solution of palladium dichloride (molar ratio diazonium salt topalladium dichloride 1:0.01) is added at 60° C. After cooling to 30° C.the mixture is added to the suspended diazonium salt.3,3,3-trifluoropropene (molar ratio diazonium salt to3,3,3-trifluoropropene 1:1.01) is introduced during 5 hours and stirringis continued until no diazonium salt can be detected. The suspension isthen ready for hydrogenation.

b) Preperation of sodium-[2-(3,3,3-trifluoro-prop- 1-yl)]-benzene-sulfonate.

Charcoal (weight ratiosodium-[2-(3,3,3-trifluoro-1-propenyl)]-benzene-sulfonate to charcoal10:1) is added to the above suspension and hydrogen is introduced during6 hours at 35° to 40° C. and a pressure of 1 bar. Suspended material isfiltered off and the pentanol solution is washed with water/sodiumhydroxide to remove sodium acetate and byproducts. Pentanole ispartially distilled off, water is added and the remaining pentanole isremoved by azeotropic destillation. The resulting solution of theproduct in water is used in the next step.

c) Preperation of 2-(3,3,3-trifluoro-prop-1-yl)]-benzene-sulfonamide.

Water is distilled off from the above solution. Chlorobenzene is addedand the remaining water is removed by azeotropic destillation. Phosgene(molar ratio of sodium-[2-(3,3,3-trifluoro-prop-1-yl)]-benzene-sulfonateto phosgene 1:2.5) is introduced at 85° to 105° C. during 5 hours in thepresence of catalytic amounts of dimethylformamide (molar ratio phosgeneto dimethylformamide 1:0.1). The solution is then treated with an excessof aqueous NH₃ (content 30%, molar ratio2-(3,3,3-trifluoro-prop-1-yl)-benzene-sulfochloride to NH₃ 1:4) at 60°C. during 1 hour and the reaction mixture is stirred for further 2hours. After cooling the precipitated is filtered off and used in thenext step.

d) Preperation ofN-(4-methoxy-6-methyl-1,3,5-tiazine-2-yl)-N'-[2-(3,3,3-trifluoroprop-1-yl)-benzenesulfonyl]-urea.

The product of the previous step is suspended in hot chlorobenzene. Inthe presence of catalytic amounts of cyclohexylisocyanate (molor ratioof product to cyclohexylisocyanate 1:0.01) phosgene (molor ratio ofproduct to phosgene 1:3) is introduced at 100° to 120° C. during 5hours. The chlorobenzene is destilled off until a concentration of 25%isocyanate is reached. This solution is added during 1 hour to asuspension of 2-amino-4-methyl-6-methoxy-triazine in chlorobenzene at90° C. The suspension is stirred for further 90 minutes and then cooled.The product is filtered off and vacuum dried. 170 kg of pure product areprepared at the pilot plant.

We claim:
 1. A process for the preparation of compounds of the formulaIa

    Ar--CHR.sub.a --CHR.sub.b R.sub.c                          (Ia),

wherein R_(a), R_(b) and R_(c) are independently of each other selectedfrom H; C₁ -C₂₀ alkyl; C₁ -C₂₀ nitriloalkyl; C₁ -C₂₀ hydroxyalkyl; C₁-C₂₀ halogenalkyl; C₁ -C₁₂ alkyl-COOR_(d), C₁ -C₁₂ alkyl-CO--NR_(e)R_(f), C₁ -C₁₂ alkyl-SO₂ OR_(d) or C₁ -C₁₂ alkyl-SO₂ --NR_(e) R_(f),wherein R_(d), R_(e) and R_(f) independently are H, C₁ -C₁₂ alkyl,phenyl, benzyl or cyclohexyl; C₁ -C₂₀ alkyl-CO; C₁ -C₂₀ alkoxy; C₁ -C₂₀nitriloalkoxy; C₁ -C₂₀ halogenalkyloxy; C₁ -C₂₀ alkylthio; C₁ -C₂₀halogenalkylthio; --SO₂ OR_(d), --SO₂ --NR_(e) R_(f), --COOR_(d) or--CO--NR_(e) R_(f), wherein R_(d), R_(e) and R_(f) have the abovemeanings; halogen; --CN; --NR_(e) R_(f), wherein R_(e) and R_(f) havethe above meanings; phenyl or benzyl which is unsubstituted orsubstituted by C₁ -C₂₀ alkyl; C₁ -C₂₀ nitriloalkyl; C₁ -C₂₀hydroxyalkyl; C₁ -C₂₀ halogenalkyl; C₁ -C₁₂ alkyl-COOR_(d), C₁ -C₁₂alkyl-CO--NR_(e) R_(f), C₁ -C₁₂ alkyl-SO₂ OR_(d) or C₁ -C₁₂ alkyl-SO₂--NR_(e) R_(f), wherein R_(d), R_(e) and R_(f) independently are H, C₁-C₁₂ alkyl, phenyl, benzyl or cyclohexyl; C₁ -C₂₀ alkyl-CO--; C₁ -C₂₀alkoxy; C₁ -C₂₀ nitriloalkoxy; C₁ -C₂₀ halogenalkoxy; C₁ -C₂₀ alkylthio;C₁ -C₂₀ halogenalkylthio; --SO₂ OR_(d), --SO₂ --NR_(e) R_(f), --COOR_(d)or --CO--NR_(e) R_(f), wherein R_(d), R_(e) and R_(f) have the abovemeanings; halogen; --CN; --NR_(e) R_(f), wherein R_(e) and R_(f) havethe above meanings, whereby R_(d) can also represent --OM or--O(M₁)_(1/2), where M is an alkali metal atom or a tertiary ammoniumgroup, having from 3 to 18 carbon atoms, and M₁ is an alkaline earthmetal atom; and Ar means C₆ -C₂₀ aryl, or C₃ -C₂₀ heteroaryl selectedfrom the group consisting of pyridine, triazine, pyrimydine andchinoline, the aryl and heteroaryl being unsubstituted or substituted byC₁ -C₂₀ alkyl; C₁ -C₂₀ nitriloalkyl; C₁ -C₂₀ hydroxyalkyl; C₁ -C₂₀halogenalkyl; C₁ -C₁₂ alkyl-COOR_(d), C₁ -C₁₂ alkyl-CO--NR_(e) R_(f), C₁-C₁₂ alkyl-SO₂ OR_(d) or C₁ -C₁₂ alkyl-SO₂ --NR_(e) R_(f), C₁ -C₂₀alkyl-CO--; C₁ -C₂₀ alkoxy; C₁ -C₂₀ nitriloalkoxy; C₁ -C₂₀halogenalkoxy; C₁ -C₂₀ alkylthio; C₁ -C₂₀ halogenalkylthio; --SO₂OR_(d), --SO₂ --NR_(e) R_(f), --COOR_(d) or --CO--NR_(e) R_(f) ;halogen; --CN; --NR_(e) R_(f) ; --OH; or --SH; by a) in a first stepreacting 1 mole equivalent of a compound of the formula IIa

    Ar--N.sub.2.sup.⊕                                      (IIa)

with at least 1 mole equivalent of a compound of formula IIIa

    CHR.sub.a ═CR.sub.b R.sub.c                            (IIIa),

optionally in the presence of an inert solvent, and in the presence of acatalytic amount of a homogeneous palladium catalyst and a base selectedfrom alkali metal salts, alkaline earth metal salts and a tertiaryammonium salt of a carboxylic acid to give a compound of the formula IVa

    Ar--CR.sub.a ═CR.sub.b R.sub.c                         (IVa),

and b) hydrogenating in a second step the compound of the formula IVaoptionally in the presence of an inert solvent and in the presence ofcatalytic amounts of a heterogeneous palladium hydrogenation catalyst,characterised in that that the homogeneous palladium catalyst is reducedto insoluble palladium metal after the step a) reaction, which issubsequently used as the heterogeneous hydrogenation catalyst.
 2. Aprocess according to claim 1, wherein the heterogeneous palladiumhydrogenation catalyst is formed in situ from the homogeneous palladiumcatalyst in the obtained step a) reaction mixture in starting thehydrogenation by introducing hydrogen.
 3. A process according to claim1, wherein a palladium support material for the heterogeneoushydrogenation catalyst is added prior to the introduction of hydrogen.4. A process according to claim 1, wherein the homogeneous catalyst isgenerated in situ or ex situ by reduction of a palladium(II) compoundand in the presence of suitable ligand-forming compounds.
 5. A processaccording to claim 4, wherein the palladium(II) compound is selectedfrom the group consisting of PdCl₂, PdBr₂, Pd(NO₃)₂, H₂ PdCl₄,Pd(OOCCH₃)₂, [PdCl₄ ]Na₂, [PdCl₄ ]Li₂, [PdCl₄ ]K₂,palladium(II)acetylacetonate,dichloro-(1,5-cyclooctadiene)palladium(II),dichlorobis-(acetonitrile)palladium(II),dichlorobis-(benzonitrile)palladium(II), π-allylpalladium(II)chloridedimer, bis-(π-methylallyl palladium(II)chloride) andπ-allylpalladium(II)acetylacetonate.
 6. A process according to claim 4,wherein the ligand-forming compounds are selected from the group ofolefins as described by the compounds of formula III,dibenzylideneacetone (dba) unsubstituted or substituted with halogen, C₁-C₄ -alkyl or C₁ -C₄ -alkoxy in the benzene rings, phosphites of formulaP(OR₇) wherein R₇ is for example phenyl, C₁ -C₆ -alkyl or a partially orperfluorinated C₁ -₆ -alkyl, and CO.
 7. A process according to claim 3,wherein activated carbon, carbon black, Al₂ O₃, SiO₂, a ceramic, glassor synthetic or naturally occurring zeolite is added as catalyst supportmaterial.
 8. A process according to claim 1 for the preparation ofcompounds of the formula I ##STR11## wherein X represents hydroxyl,--OM, --O(M₁)_(1/2) or NH₂, where M is an alkali metal atom or atertiary ammonium group, having from 3 to 18 carbon atoms, and M₁ is analkaline earth metal atom,Y is H, Cl, F or Br, R₁ is H, F, Cl, Br or--COOR₃, R₂ is --COO(C₁ -C₄ -alkyl, --(CO)R₃ or C₁ -C₂ -alkyl which isunsubstituted or substituted by halogen atoms, and R₃ is H or C₁ -C₄-alkyl, by a) in a first step reacting 1 mole equivalent of a compoundof the formula II ##STR12## with at least 1 mole equivalent of acompound of formula III

    CHR.sub.1 ═CHR.sub.2                                   (III),

optionally in the presence of an inert solvent, and in the presence of acatalytic amount of a homogeneous palladium catalyst and a base selectedfrom alkali metal salts, alkaline earth metal salts and a tertiaryammonium salt of a carboxylic acid to give a compound of the formula IV##STR13## and b) hydrogenating in a second step the compound of theformula IV optionally in the presence of an inert solvent and in thepresence of catalytic amounts of a hydrogenation catalyst, characterisedin that the homogeneous palladium catalyst is reduced to insolublepalladium metal in the step a) reaction mixture, which is subsequentlyused as the heterogeneous hydrogenation catalyst.
 9. A process accordingto claim 8, wherein the reducing agents used are CO, H₂, formates,primary or secondary C₁ -C₈ -alkanols, hydrazine, amines and mixtures ofCO with alkanols or water.
 10. A process according to claim 8, whereinthe catalyst added is Pd(dba)₂, Pd(dba)₃.solvent, Pd₂ (dba)₃ or Pd₂(dba)₃.solvent, where the abbreviation "dba" stands for dibenzylideneacetone, which is unsubstituted or substituted in the aromatic part asdefined in claim
 6. 11. A process according to claim 8, wherein thepalladium catalyst is used in an amount of 0.01 to 5 mole %, based onthe diazonium salt of formula II according to claim
 8. 12. A processaccording to claim 8, wherein a base is present which is selected fromLi--, Na--, K--, NH₄ --, Mg--, Ca-- and NH(C₁ -C₁₈ -alkyl)₃ -salts ofcarboxylic acids.
 13. A process according to claim 8, wherein apalladium support material for the heterogeneous hydrogenation catalystis added prior to the introduction of hydrogene.
 14. A process accordingto claim 13, wherein activated carbon, carbon black, Al₂ O₃, SiO₂, aceramic, glass, or synthetic or naturally occurring zeolite is added ascatalyst support material.
 15. A process according to claim 8, wherein asmall excess of alkene of formula III is used.
 16. A process accordingto claim 8, wherein the homogeneous palladium catalyst is reduced withhydrogen.
 17. A process according to claim 8, for the preperation ofsodium-2-(3,3,3-trifluoroprop-1-yl)-benzene-sufonate.